It is known in the past to inject a melted material, such as metal, into a die cavity with an injection device having a shot sleeve and a ram. In some instances, a vacuum is pulled from the edge of the die cavity which pulls the melted material into the shot sleeve through a fill tube which is disposed within a crucible of melted material. As an example of this method, the reader should refer to Weingarten (U.S. Pat. No. 4,476,911) and Gibbs die casting literature.
It is also known to dispose a fill tube, which is in fluidic communication with the die cavity, in a crucible of melted material within a pressure vessel (see U.S. Pat. No. 4,573,517 to Booth et al.). The die cavity is evacuated through the fill tube in the melt inside a pressure vessel. The die cavity is filled with molten material by pressurizing the pressure vessel. These methods suffer because the fill tube must be heated and is constantly disposed within the melted material, it is prone to clogging, reaction, and breakage.
The present invention overcomes the problem of clogging by eliminating the fill tube and instead utilizes a device, isolated from the injection device, for providing the melted material into an injection device within a vacuum chamber.